To cite package ‘n2kupdate’ in publications use:

  Onkelinx T (2019). _n2kupdate: Auxiliary Functions to Update the
  n2kresult Database_. R package version 0.1.1,
  <https://github.com/inbo/n2kupdate>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {n2kupdate: Auxiliary Functions to Update the n2kresult Database},
    author = {Thierry Onkelinx},
    year = {2019},
    note = {R package version 0.1.1},
    url = {https://github.com/inbo/n2kupdate},
  }